Electric attachment plug



Oct. 13, 1942. w, J, scRlMsHAw 2,298,973

ELECTRIC ATTACHMENT PLUG Filed Dec. 23,'1940- .59 3 T47: J. 'ot'lmsia/W Patented ct. 13, 1.942

UNlTED STATES PATENT OFFICE 2,298,973 y ELECTRIC ATTACHMENT PLUG Walter J. Scrimshaw, New Orleans, La. Application December Z3, `1940, Serial No. 371,435 1 claim. (ci. 173-343) This invention relates to electric connectors. v

An object of this invention is to provide in combination a pair of plug type connectors, one of which is adapted to be threadably engaged with an electric outlet receptacle and the other of which is adapted to be engaged with the first member.

Another object of this invention is to provide an electrical connector means which is so constructed that the two parts forming the connector can be readily coupled together without danger of a short circuit between the contact members thereof.

Another object of this invention is to provide an electric connector means including a combined socket and plug which is adapted to be inserted in an outlet receptacle or a socket anda plug type connector which is adapted to removably engage in the socket of the first element, the second connector element being in the form of an axially disposed plug member.

A further object of this invention is to provide a pair of connector members which are adapted to be coupled together in such a manner that they will not readily become disengaged but which may be separated when desired without possibility of a short circuit or a shock due to a short circuit.

To the foregoing objects and to others which may hereinafter appear, the invention consists of the novel construction, combination and arrangement of parts as will be more specifically referred to and illustrated in the accompanying drawing wherein are shown embodiments of the invention, but it is to be understood that changes, variations and modifications may be resorted to which fall within the scope of the invention as claimed.

In the drawing:

Figure l is a longitudinal section of an electrical connector constructed .according to an embodiment of this invention.

Figure 2 is a longitudinal section taken through the socket member forming part of the connector.

Figure 3 is a fragmentary sectional view taken on the line 3 3 of Figure 2.

Figure 4 is a sectional view taken on the line 4-4 of Figure l.

Figure 5 is a detail side elevation of the male element forming part of this connector.

Referring to the drawing, the numeral I0 designates generally a combined plug and socket body which is of substantially cylindrical configuration and which at its outer end is formed with a flange I I. The body II is provided axially thereof with a socket I2 which extends inwardly from the outer end thereof and terminates inwardly from the inner wall I3. The body I0 has snugly engaged thereabout a threaded sleeve I4 which at its inner end is provided with an annular flange I5 engaging against the inner face of the inner end wall I3. l

Preferably the body I0 is formed of insulating material and may be cast with threads I6 which are adapted to be engaged by the threads of the sleeve I4. The sleeve I4 together with the ange I5 is formed of metal and comprises one contact which is adapted to be engaged with threads carried by an electric socket, which may be part of an electrical convenience receptacle or any other threaded light socket.

An elongated flat resilient contact member I1 is loosely disposed in a passage I8, which is formed in the body I0 and which is disposed at an inclination to the length of the socket I2. The passage I8 opens as at I9 into the socket I2 adjacent the outer end of the socket and the opposite end of the passage I8, communicates with a cutout 20 which is formed 'in the end wall I3 in a position confronting the flange I5. The inner end of the contact member I'I is formed with an acutely disposed extension 2I, which is secured by means of a rivet or other fastening device 22 to the inner face of the flange I5. The extension 2l is adapted to engage within the cutout 20.

The opposite or outer end of the contact member is bent obtusely as at 23 and is adapted to engage one side of a contact member as will be hereinafter described which is carried by the center plug of the connector. An insulated plate 24 of substantially disc conguration is secured against the outer face of the ange I5 by means of a fastening device 25 in the form of a rivet. The fastening device 25 also constitutes a center contact, which is adapted to engage with the center contact carried by the socket within which the body member IIJ is adapted to engage.

A washer 26 is interposed between the head of the rivet 25 and insulated washer or plate 24. A substantially U-shaped contact member 2'I is disposed within the socket I2 and the bight 28 of the U-shaped member 2'I engages against the outer face of the end wall I3. The rivet or fastening device 25 engages through the bight 28 and rmly holds the contact member 21 in the socket I2.

A detachable connector member generally designated as 29 is adapted to be engaged with the body I and comprises a cup-shaped insulated member which on the inner face thereof is provided with a pair of substantially triangular lugs 3| and 32. The lugs 3| and 32 are formed integral with the cup-shaped member 39, being preferably cast or molded out of the insulating material of which the cup-shaped member 30 is also formed with a central opening 33 through which a conductor sheave 34 is adapted to engage.

An axially disposed insulated plug member 35 is disposed axially of the cup-shaped member 39 and has a portion thereof projecting inwardly of the open side of the cup-shaped member 3i). A cylindrical metallic sleeve 36 tightly engages about the insulated plug member 35 and is provided with an extension 31 which extends inwardly in the direction of the cup-shaped member 30.

A right angular extension 38 is formed integrally with the extension 31 and a screw 39 engages through the extension 38 and is threaded into the lug 32. A washer 4i) is adapted to be interposed between the extension 38 and the adjacent face of the lug 32. One end of an electrical conductor 4I is adapted to be interposed between the head of the screw 39 and the outer side of the extension 38. The cylindrical contact member 35 is positioned intermediate the ends of the insulated plug member 35 and is adapted when in operative position to frictionally engage against the contacting end 23 of the resilient contact member II.

A substantially spherical-shaped contact member 42 is fixed to the outer end of a wire 43 which extends through an axially disposed bore I 44 formed in the plug 35. The outer end of the plug 35 is bevelled as at 45 and provides a stop which is adapted to be engaged by the outwardly bent end portions 45 of the parallel legs 41 carried by the U-shaped contact member 21. Preferably the parallel legs 4'! are each provided with anelongated slot 48 in which a portion of the spherical contact member 42 is adapted to engage. The wire 43 at its outer end is provided with a right angular extension 49 which is looped about a headed screw 5I] threaded into the lug 3I.

A second conductor 5I which extends through the sheave 34 is adapted to be interposed between the head of the screw 59 and the extension 49. A washer 52 is also interposed between the adjacent face of the lug 3l and the extension 49. The wire 43 including the extension 49 and the contact member 35 including the right angular extension 39 provides a means whereby the insulated plug 35 will be held axially or the cupshaped body 39.

In the use and operation of this electric connection, the combined plug and socket member I0 is adapted to be threaded into a socket, such as a socket in a convenience receptacle or an electric bulb socket with the center Contact member or rivet 25 engaging the center contact of the socket. The threaded sleeve I4 also engages the side Wall of the electric socket and provides a contact for connection with the electric source.

The removable plug member 29 may be inserted in the combined socket and plug member Il) by disposing the center plug member 25 axially of the socket I2, the plug member 35 being moved endwise until the substantially spherical contact member 42 engages the U-shaped contact member 21. At this time, the cylindrical contact member 36 will also be engaged with the resilient contact member I1 so that a complete circuit will be formed between the wires 4I and 5I and the electric light source with which the combined plug and socket member II) is engaged.

The spherical contact member 42 is spaced a sufficient distance from the adjacent end of the cylindrical contact member 38 so that when the center plug 35 is inserted in the socket I2, this center plug will not short circuit or bridge the two contact members II and 21.

With an electrical connector means as constructed according to this invention, it will not be necessary for the person inserting the connector member 29 in the socket I2 to position the plug member 35 with the contact 42 in any particular axial position with respect to the socket I2. In the use of connectors embodying a pair of contact prongs, it is necessary that the two prongs be turned in a position for registry with the openings provided in the plug whereas with a connector constructed according to this invention, the removable plug member 29 can be inserted irrespective of the circumferential relation of the plug member 29 with respect to the combined socket and plug member I0.

What I claim is:

An electrical connector comprising a one-piece, hollow, peripherally threaded insulating body having a closed inner and an open outer end, said body being formed axially with a socket opening at said outer end, a cutout in and disposed diametrically of the outer periphery 0f said inner end and an inwardly inclined passage opening at its rear end into the outer portion of said cutout and at its front end into said socket rearwardly of the mouth of the latter and rearwardly of the said outer end, said cutout opening at the outer side face of said body, a threaded sleeve of conducting material encompassing and threadedly engaging with said body and formed with an inwardly extending annular flange seated against said cutout, an inclined resilient contact disposed in said passage and extending at one end into said socket and at its other end into said cutout, an extension on the other end of said contact arranged in said cutout, an insulating plate positioned against the outer face of said flange, means for securing said extension against the inner face of said flange, a U-shaped contact member arranged within and having its bight positioned against the base of said socket, and means for securing said U-shaped contact member, said body and said insulating plate together` said U-shaped contact member having its legs formed lengthwise thereof with slots.

WALTER J. SCRIMSHAW. 

